Let's keep it civil, shall we? I won't make negative comments about your character or motives. Can you please do the same?
It seems the crux of our disagreement is you guys feel any mathematical analysis is suspect from the get-go.
JJF: "Can you use mathematics to explain these things? - You might well try, but that won't actually answer the question "why"."
IncarnateX: "used as a source of explanation (of causes to the 7 note scale) rather than a mean of description (of the already established 7 note scale) [the math] becomes misleading and also very ethnocentric"
This seems a matter of opinion, not fact. I don't think there's any way to prove or disprove that the mathematical validity of 5 notes or 7 notes has to do with their historical prominence. So perhaps we can agree to respect each other's opinions?
Finally, I'm not making any value judgements about 8-note scales or scales with large gaps or anything. I can see where you might have gotten that impression from my comment about the tonic - m2 - M2 - P4 - tritone - P5 - m7 - M7 - 8ve scale. I'll withdraw that comment, since it's not my main point anyway.
Musicologo: Interesting theory. It's really hard to pick out the 11th and 13th harmonic in a string or wind instrument by ear. I've done it, but it's hard. Do you have any evidence that the ancient Greeks or whoever used these intervals?
murnau: Nice link. This guy is saying much of the same things I'm saying, that 12 fifths add up to about an octave, as do 19 fifths, and therefore they are useful frameworks.
D.H. Miltz: Point taken. Sorry about that!